The platohistory.org website is the home of the PLATO History Foundation and the archive for information about the history and significance of the PLATO computer system and its online community.

The Foundation's principal focus is to advance the public awareness of the history, significance, and importance of the PLATO computer system and its online community, and to tell the story of the people who designed, built, and used the system.

The PLATO system was created in 1960 at the University of Illinois. Initially it ran as a one-terminal system connected to the ILLIAC computer. By 1963, the system was running on a CDC 1604 with multiple simultaneous users. By 1972, the system had expanded to run a thousand simultaneous users on a CDC CYBER mainframe. Control Data Corporation began marketing PLATO commercially in 1976, resulting in PLATO system installations in dozens of cities around the world. Many of these systems were interconnected, enabling email and remote logins through the network. For nearly ten years, there were more users on PLATO than there were on ARPANET, the precursor to the Internet.

This site is maintained by Brian Dear, who has conducted years of research on the history of PLATO.